This invention relates to programmable logic device technology, and more particularly, to computer systems in which programmable logic is reconfigured to optimize the ability of the system to handle a given application.
The only programmable element in a conventional computer architecture is the microprocessor. The microprocessor is manufactured with a fixed instruction set that cannot be customized for specific applications. The microprocessor is flexible in that it can run virtually any software-implemented function of an application. The speed of execution of a given function, however, is generally substantially slower when implemented to execute on a microprocessor. This is because software-implemented functions must be fairly complex to accommodate the microprocessor's generic instruction set.
With conventional computer architectures, software will typically only run on a limited range of platforms. If an application engineer decides to write an application to be run on a given microprocessor, the instruction set the application engineer may use is limited to the one permanently resident on the microprocessor. The application engineer must therefore select whether an application is better suited for a hardware platform or a software platform. Although software platforms are often preferred due to the inflexibility and inefficiency of hardware-based systems, in many cases, the generic instruction set resident on a microprocessor results in inadequate performance for a particular type of software application. For example, graphics-intensive applications usually require hardware that is specifically suited for the particular graphical elements of the application, such as 3-D rendering. In order to circumvent the difficulties associated with programming for a hardware platform, engineers turn to software, which in many cases greatly reduces the application's speed.
Recently, the notion of a reconfigurable computer based on programmable logic devices has been proposed. The goal of a reconfigurable computer is to increase performance over a conventional computer by providing parallelism and rapid execution times through the use of customizable hardware. Increased flexibility can be achieved by using programmable logic devices, because the logic of such devices may be reconfigured by loading new configuration data into the devices. This allows the reconfigurable computer to provide a large number of instruction sets, rather than a single instruction set for a conventional computer. A greater number of functions may be provided using a fixed amount of hardware if the computer uses reconfigurable logic.
It is an object of the present invention to provide improved reconfigurable computers based on programmable logic devices that may be reprogrammed to optimize the ability of the computer to handle a given application.